transfer data between computers

 1. netcat

receiving machine:

iptables -A INPUT -p tcp --dport 1440 -s $remoteIP -i br0 -j ACCEPT

nc -l -p 1440 |  dd bs=16M of=destimage

sending machine

pv -r -t -b -e sourceimage.iso |nc virt3 1440 -i 1

(dd or cat can be used instead of pv)
(netcat option -i 1 (idle timer) is -q 1 at other implementation)

with compression: 

serv1# nc -l -p 1440 | pigz -d | dd bs=16M of=/path/destimage

serv2# dd if=srcimage bs=16M |pv|pigz -1|nc virt3 1440 -i 1

in one command:

(zstd je alternativa, mozna rychlejsi)

ssh -n -f dest.example.com "bash -c 'nc -l -p 1440 |pigz -d |dd bs=16M of=/mnt/1/destimage>/dev/null 2>&1 &'" ;
sleep 2 ; dd if=srcimage bs=16M |pv|pigz -1|nc virt3 1440 -i 1 

2. ssh: 

 cat /dev/xxx | zstd | ssh dest.example.com "zstd -d | dd of=/dev/xxx" (nezkoušeno)